Biodegradable Polymers Study Guide Flashcards
What are the advantages of synthetic biodegradable polymers over that of natural ones?
tailor-able properties
predictable lot to lot uniformity
free from concerns of immunogenicity
reliable source of raw materials
what are some factors that accelerate polymer degradation?
more hydrophilic backbone
more reactive hydrolytic groups in the backbone
less crystallinity
more porosity
small device size
**what are biodegradable polymers
are a specific type of polymer that breaks down after its intended purpose to result in natural byproducts.
What are the four steps of polymer degradation?
water sorption
reduction of mechanical properties (modulus and strength)
reduction of molar mass
weight loss
*Name two effects of bioerosion on polymer properties
- changes in the appearance of the device
- changes in the physiomechanical properties
- swelling
- deformation
- structural disintegration
- weight loss
- loss of function
Describe two types of bioerosion.
surface erosion-sample is eroded from the surface
bulk degration-degration takes place throughout the whole of the sample
***describe the polymer degration mechanism
cleaveage of cross-links between chains
cleavage of side chains
cleavage of polymer backbone
combination of above
give examples of natural polymers
give examples of synthetic polymers
Natural polymers Fibrin Collagen Chitosan Gelatin Hyaluronan \
Synthetic polymers PLA, PGA, PLGA, PCL, Polyorthoesters … Poly(dioxanone) Poly(anhydrides) Poly(trimethylene carbonate) Polyphosphazenes …
what is the difference between surface errosion and bulk
surface erosion is where the sample is eroded from the surface. bluk degration is where degration takes place throught the whole of the sample.
Are all polymers biodegradable?
no. for example petroleum isnt. and polyester.
**Are all biodegradable polymers ideally biocompatible?
_
State three applications of biodegradable polymers.
in regards to tissue engineering making polymer scaffolds. tissues are usually grown onto these
biodegradable materials in orthopedic devices to make screws . if they are biodegradable no need
sutures
name three factors that determine the rate of bioerosion
initial molecular weight of the polymer
fabrication process
presence of catalysts, additives or plasticizers
geometry of the implanted device (survace/volume ratio)
polymer less permeable to water in glassy state
Name two benefits to having biodegradable polymer in the body.
- biodegradable devices need no removal
- avoid stress shielding
- offer tremendous potential as basis for controlled drug delivery
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Which one of the following is a biodegradable polymer? polyethylene polyvinyl chloride nylon polydioxanone dacron
polydioxanone
